否运算符:~ 加1取反

console.log(~-11);    //10
console.log(~-1);     //0
console.log(~0);      //-1

<a href="javascript:void(0)">单击此处什么也不会发生</a>

<a href="javascript:void(alert(‘Warning!!!‘))">点我!</a>



function getValue(){
  var a,b,c;
  a = void ( b = 5, c = 7 );
  document.write(‘a = ‘ + a + ‘ b = ‘ + b +‘ c = ‘ + c );
}

//a = undefined b = 5 c = 7